The ginseng is placed in the drying room in layers, and there must has sufficient space between the layers. Do not place them too closely in order to facilitate ventilation and dehumidification. The hot air circulation parts make the temperature and steam flow in the whole drying room uniform, and take away water molecules in time. When drying ginseng, the temperature of the drying room should not be too high. Generally, the temperature parameter range should be set between 45°C-50°C, the minimum is 30°C, and the relative humidity is about 60%. The drying temperature is from low to high, and then repeated from high to low. Continue drying until the moisture content is within 10%.